We suspect our reaction may be out of step with the general consensus of press at our Berlin Film Festival screening of the “The Croods” today, if the guffaws and applause were anything to go by, but really that had us kind of baffled. The DreamWorks film, from writer/directors Chris Sanders (“How to Train Your Dragon,” “Lilo & Stitch“) and Kirk Di Micco (“Space Chimps“), features a starry voice cast in Nicolas Cage, Emma Stone, Ryan Reynolds, Catherine Keener, Cloris Leachman and Clark Duke, and an appropriately high concept: the Croods are a family of cavemen who have to evolve suddenly when faced with cataclysmic natural disasters and the arrival of a young Homo Sapiens with the ability to make fire.

But while the premise, with its roots in ancient human history, is quite promising, it doesn’t appear to have been fertile enough for Sanders and DiMicco who elect to set most of it in an entirely fantastical past, populated with wonderfully rendered but completely fabricated animals and plant life, and characterized by impossible physics. This uneasy marriage of fantasy and prehistory meant that to us the film too often took the easy way out in both its humor — slapstick, lots of boinging and boinking and hurtling across large spaces to crash into something and have another something land on top — and its storyline. It’s hard to invest in any stakes when we literally have no clue what deux ex machina exotic creature or seismic activity might be waiting around the next corner to change the odds all over again.

Perhaps we have come to have such a high bar set for animation in recent years that we were simply expecting something that could surprise and dazzle us visually as much as this does here (the 3D is well worth it, for once), while at the same time adhering to internally coherent logical rules. Which is not to say it needs to be realistic — in “Up” we were perfectly content with a world of talking dogs and flying houses, because of how subtly yet rigorously the parameters of that world were established and never broken. But in “The Croods” these rules are never set out, and with the goalposts constantly moving, we can’t really invest in the group’s quest at all.

The other casualty is the non-boing-bash-bang humor, which becomes somewhat rudderless because, lacking a recognizable framework to riff off, the central “Flinstones” anachronism — in which the caveman family dynamic is comically similar to that of a modern family — can’t really gain much traction: they might as well be aliens. And with only Eep and Grug having any sort of personality aside from the purely one-note (the savage baby, the dim son, the nagging mother in law, the supportive nonentity wife) and a character design that teeters perilously close to ugly at times, the film overall lacked the sort of lovability we might expect, to the point of charmlessness.

Eep (Stone) is a cavegirl/Neanderteen who, unlike the rest of her family, has an adventurous, questing spirit and a love of sunshine and light. This brings her into frequent conflict with her strong and protective but traditionalist father Grug (Cage), who believes the family should stay in the darkened cave as much as possible to avoid the various perils of outside life. Of course, this is that kind of animated world in which the concepts of “grounding” and “harpy mother-in-law” predate “shoes,” but fine, ok, whatever. The narrative problems really arise when, after an extended gonzo opening that is very fast and very noisy and features the family hurtling around trying to steal an egg for sustenance, Eep sneaks out one evening and follows a burning cinder back to its source: a fire lit by Modern Man, in the form of Guy (Reynolds).

While it’s never really explained where Guy came from or how he learned to make fire, or if there are any other of his kind around, he and Eep form a connection across (presumably) species, or at least evolutionary barriers, and he soon charms the rest of her family with his great ideas — shoes for walking on rough surfaces, an animal/pet called “Belt” who holds up his pants, and a neat line in creating coquettish puppets to distract potential predators. All except Grug, of course, who has to come to terms with his daughter’s crush and who feels increasingly marginalized by the adaptable and intelligent Guy, to the point of competing with him in a flat-out weird sequence in which Cage/Grug affects a bizarre accent and what looks like a rasta wig and invents sunglasses. But with an ill-defined series of earthquakes, explosions and landfalls having put paid to any possibility of life remaining the same, the family is forced to head with Guy towards some equally ill-defined safe place, which he calls “tomorrow,” through a landscape of exotic and dangerous wildlife that seems to stem from some kind of really, really late Cambrian explosion. Why they will be safe there from the apocalyptic sundering of mountains and erupting of ash clouds is unclear, but it does make for some spectacular visuals.

Perhaps younger children (or a very tired, end-of-festival crowd, if that’s not too catty) will be amused enough by the day-glo fluorescent colors, fantastical landscapes and zany antics to not mind the lack of the kind of story coherence and more sophisticated humor we’ve come to expect from big-budget studio animation. As for us, although we found ourselves momentarily taken in by the emotional manipulation of the climax (Daddy issues, I guess), more lasting was the feeling of how unearned that was. Because though it’s impressive in many technical and surface ways, “The Croods” lets us down on the essentials of character and story, and no amount of late-stage father/daughter bonding or vertiginous 3D cliffside tumbling can make up for that. [B-/C+]